Question

guys please help me to solve ​

Answer 1

Answer:

Given-: a:b =3:4 ,

x:y =5:7

Since,

Let the ratio constant be z.

i.e. a:b =3z:4z

and, x:y =5z:7z

ATQ-:

(3ax-by):(4by-7ax)

3{(3z*5z)-(4z*7z)}:4{(4z*7z)-7(3z*5z)}

$3(15 {z}^{2} ) - 28 {z}^{2}) \div 4(28 {z}^{2} ) - 7(15 {z}^{2})$

$45 {z}^{2} - 28 {z}^{2} \div 112 {z}^{2} - 105 {z}^{2}$

$17 {z}^{2} \div 7 {z}^{2}$

17/7

Answer 2

Solution :

It is given that :

• a : b = 3 : 4
• x : y = 5 : 7

Let us assume that a = 3k, and b = 4k

And x = 5j and y = 7j .

To find :

• Ratio of (3ax - by) : (4by - 7ax)

Substituting the assumed values :

• ( 3 * 3k * 5j - 4k * 7j ) : ( 4 * 4k * 7j - 7 * 3k * 5j )
• ( 45jk - 28jk ) : ( 112 jk - 105 jk)
• ( 17 jk ) : ( 7 jk )

> 17 : 7

Thus, the required ratio is 17 : 7.

This is the answer.

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